Apparatus for scrambling/descrambling data by word-by-word processing
First Claim
1. A scrambling/descrambling apparatus for scrambling/descrambling input data to produce output data comprising:
- storing means for storing a data word, a bit invert flag, and numerical data;
bit shift operating means for performing, on receiving a bit of data to be outputted or a bit of input data, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word;
randomizing/derandomizing means for randomizing or derandomizing the input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting said bit of said data to be outputted to develop output data;
count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and
count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag;
said storing means holding a second and a third data word, bits of which corresponding in position to a particular bit of said first data word are a ZERO and a ONE, respectively;
said count controlling meansreading selectively either one of said second and third data words out of said storing means depending on the value of said bit which is inputted to said bit shift operating means;
Exclusive-ORing said data word read out and said first data word;
performing a masking operation with a data word resulting from the Exclusive-ORing for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits;
replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state.
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Abstract
A scrambling/descrambling apparatus has a data memory for storing a data word, a bit invert flag, and numerical data. A bit shift operating section performs, on receiving a bit of data to be outputted or a bit of input data, a bit shift operation with that bit and stores resultant data in the data memory in the form of a first data word. A randomizing/derandomizing section randomizes or derandomizes the input data by using the first data word and based on a generating polynomial and, depending on a state represented by the bit invert flag, inverts the bit of the data to be outputted to develop output data. A count processing section increments or decrements the numerical value stored in the data memory and, depending on the numerical value, selectively sets the bit invert flag to a predetermined state. A count controlling section replaces the numerical value with a predetermined initial value on the basis of the first data word and bit invert flag. The data memory holds a second and a third data word, bits of which corresponding in position to a particular bit of the first data word are a ZERO and a ONE, respectively. The count controlling section reads selectively either one of the second and third data words out of the data memory depending on the value of the bit which is inputted to the bit shift operating section, Exclusive-ORs the data word read out and the first data word, performs a masking operation with a data word resulting from the Exclusive-ORing for validating a bit corresponding in position to the particular bit position of the first data word while invalidating the remaining bits, and replaces the numerical value with the initial value when a data word resulting from the masking operation is indicative of a ZERO or when the bit invert flag is in the predetermined state. Alternatively, the count controlling section may read the first data word out of the data memory and, depending on the value of the bit which is inputted to the bit shift operating section, NOT or transfer the first data word, performs a masking operation with a data word representative of a result of NOTing or that of transfer for validating a bit corresponding in position to the particular bit position of the first data word while invalidating the remaining bits, and replace the numerical value with the initial value when a data word resulting from the masking operation is indicative of a ZERO or when the bit invert flag is in the predetermined state.
10 Citations
24 Claims
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1. A scrambling/descrambling apparatus for scrambling/descrambling input data to produce output data comprising:
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storing means for storing a data word, a bit invert flag, and numerical data; bit shift operating means for performing, on receiving a bit of data to be outputted or a bit of input data, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; randomizing/derandomizing means for randomizing or derandomizing the input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting said bit of said data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding a second and a third data word, bits of which corresponding in position to a particular bit of said first data word are a ZERO and a ONE, respectively; said count controlling means reading selectively either one of said second and third data words out of said storing means depending on the value of said bit which is inputted to said bit shift operating means; Exclusive-ORing said data word read out and said first data word; performing a masking operation with a data word resulting from the Exclusive-ORing for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (2, 3, 4, 8)
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5. A scrambler for scrambling input data to produce output data, comprising:
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storing means for storing a data word, a bit invert flag, and numerical data; bit shift operating means for performing, on receiving a bit of data to be outputted, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; randomizing means for randomizing input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting said bit of said data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding a second and a third data word, bits of which corresponding in position to a particular bit of said first data word are a ZERO and a ONE, respectively; said count controlling means reading selectively either one of said second and third data words out of said storing means in association with the value of said bit which is inputted to said bit shift operating means; Exclusive-ORing said data word and said first data word; performing a masking operation with a data word resulting from the Exclusive-ORing for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (6, 7)
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9. A descrambler for descrambling input data to produce output data comprising:
- storing means for storing a data word, a bit invert flag, and numerical data;
bit shift operating means for performing, on receiving a bit of input data, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; derandomizing means for derandomizing the input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting a bit of data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding a second and a third data word, bits of which corresponding in position to a particular bit of said first data word are a ZERO and a ONE, respectively; said count controlling means reading selectively either one of said second and third data words out of said storing means in association with the value of said bit which is inputted to said bit shift operating means; Exclusive-ORing said data word and said first data word; performing a masking operation with a data word resulting from the Exclusive-ORing for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (10, 11, 12)
- storing means for storing a data word, a bit invert flag, and numerical data;
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13. A scrambling/descrambling apparatus for scrambling/descrambling input data to produce output data, comprising:
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storing means for storing a data word, a bit invert flag, and numerical data; bit shift operating means for performing, on receiving a bit of data to be outputted or a bit of input data, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; randomizing/derandomizing means for randomizing or derandomizing the input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting said bit of said data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding said first data word; said count controlling means reading said first data word out of said storing means and, depending on the value of said bit which is inputted to said bit shift operating means, NOTing or transferring said first data word; performing a masking operation with a data word representative of a result of said NOTing or said transfer for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from said masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (14, 15, 16)
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17. A scrambler for scrambling input data to produce output data, comprising:
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storing means for storing a data word, a bit invert flag, and numerical data; bit shift operating means for performing, on receiving a bit of data to be outputted, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; randomizing means for randomizing input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting said bit of said data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding said first data word; said count controlling means reading said first data word out of said storing means and, depending on the value of said bit which is inputted to said bit shift operating means, NOTing or transferring said first data word; performing a masking operation with a data word representative of a result of said NOTing or said transfer for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (18, 19, 20)
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21. A descrambler for descrambling input data to produce output data, comprising:
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storing means for storing a data word, a bit invert flag, and numerical data; bit shift operating means for performing, on receiving a bit of input data, a bit shift operation with said bit and storing resultant data in said storing means in a form of a first data word; derandomizing means for derandomizing the input data by using said first data word and based on a generating polynomial and, depending on a state represented by said bit invert flag, inverting a bit of data to be outputted to develop output data; count processing means for incrementing or decrementing the numerical value stored in said storing means and, depending on said numerical value, selectively setting said bit invert flag to a predetermined state; and count controlling means for replacing said numerical value with a predetermined initial value on the basis of said first data word and said bit invert flag; said storing means holding said first data word; said count controlling means reading said first data word out of said storing means and, depending on the value of said bit which is inputted to said bit shift operating means, NOTing or transferring said first data word; performing a masking operation with a data word representative of a result of said NOTing or said transfer for validating a bit corresponding in position to said particular bit position of said first data word while invalidating the remaining bits; replacing said numerical value with said initial value when a data word resulting from the masking operation is indicative of a ZERO or when said bit invert flag is in said predetermined state. - View Dependent Claims (22, 23, 24)
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Specification